With the development of data storage techniques, various data storage devices have been capable of providing a higher data storage capacity for a user, and a data access speed is increased to a great extent. Apart from improving the data storage capacity, the user puts forward a growing demand for higher data reliability and a shorter response time of the storage system.
Nowadays, a technical solution based on a multi-level storage medium of different access speeds for establishing a storage system has been developed. For example, frequently used data may be loaded from a low access speed storage device to a cache device which has a high access speed, and further, the cache device is used to respond to the access request from an outside of the storage system. This technical solution may improve data response efficiency to a certain degree. However, when the storage device is failed, the cache device cannot acquire the response conditions of the storage device, and still sends a large amount of internal access requests, causing the storage device unable to respond to the user access requests within an effective time. Consequently, how to dynamically control the internal access request based on the operating conditions of the storage device becomes a hot issue.